Unraveling the depuration mechanisms of metals in the burrowing crab (Neohelice granulata Dana, 1852): Biochemical biomarkers, metal-rich granules and bioaccumulation patterns.

We studied the depuration mechanisms of metals (Cd, Cu, Pb, Zn, Mn, Ni, Cr, Fe) in Neohelice granulata, from sites with different human impacts (PC, a more impacted site and VM, a less impacted one). Our objectives included assessing metal concentrations (essential and non-essential) before and after depuration treatment, evaluating biochemical biomarkers (non-enzymatic and enzymatic) pre and post-treatment, and determining the role of metal-rich granules (MRG) in depuration. We observed variability in metals and biomarkers post-depuration, with no significant differences observed in PC, while Cd and Mn increased and Ni, Cu, and Fe decreased in VM. Integrated biomarkers' response indicated the prevailing antioxidant capacity in depurated organisms. Lipid peroxidation changes were insignificant, except in depurated-VM where values increased. MRG showed a significant decrease only for Mn and Fe, suggesting they were not the primary depuration structure. We concluded that depuration might depend on the species, gender and contamination history.

Assessment of metal contamination in an urbanized estuary (Atlantic Ocean) using crabs as biomonitors: A multiple biomarker approach.

Estuarine environments, which are complex and sensitive coastal system, and are the final receptacle of several human wastes. Consequently, biomonitoring contaminants, such as metals, within these environments and developing scientific-based tools to conserve them have become particularly importat in recent years. Therefore, in the present study, we determined the levels of certain metals (Cd, Cu, Pb, Zn, Mn, Ni, Cr and Fe) both in sediments and in a key ecological benthic species, the burrowing crab Neohelice granulata, in sites of the Bahía Blanca estuary (SW Atlantic Ocean) with different anthropogenic impacts. We combined these records with geochemical indices and enzymatic and non-enzymatic biochemical biomarkers as early warning signals of contamination and damage to establish an integrated metal contamination profile. Our results indicated that some metals like Cu moderately contaminate the estuary and that the primary input of metals in this area is due to malfunctioning sewage discharges. Crabs exhibited the following pattern of metal accumulation: Fe ≥ Cu > Zn > Mn > Ni > Cd. Pb and Cr were under the method detection limit, and Cu was probably bioaccumulated from sediments. Metal concentrations showed significant differences according to the sites and seasons (p > 0.05) and not strictly to the crab gender. Besides, a similar pattern was observed for biomarkers, and the integrated biomarker response allowed establishing different oxidative stress patterns, according not only to human impacts but also to the seasonal physiological needs of this species and environmental endpoints (salinity, temperature, and pH). This work demonstrates that environmental factors also affect the metal influx in crabs and the activity of biomarkers beyond the source and fate of these elements. This information is vital for future integrated monitoring programs.

The Acoustic Dimension of Reading: Does Musical Aptitude Affect Silent Reading Fluency?

Fluent reading in a foreign language includes a complex coordination process of visual and auditory nature as the reading brain transforms written symbols into speaking auditory patterns through subvocalization (inner voice). The auditory information activated for reading involves the projection of speech prosody and allows, beyond letters and words decoding, the recognition of word boundaries and the construction of the melodic contours of the phrase. On the one hand, phonological awareness and auditory working memory have been identified in the literature as relevant factors in the reading process as skilled readers keep the acoustic information in their auditory working memory to predict the construction of larger lexical units. On the other hand, we observed that the inclusion of musical aptitude as an element belonging to the acoustic dimension of the silent reading aptitude of adults learning a foreign language remains understudied. Therefore, this study examines the silent reading fluency of 117 Italian adult students of Spanish as a foreign language. Our main aim was to find a model that could show if linguistic, cognitive and musical skills influence adults' silent reading fluency. We hypothesized that learners' contextual word recognition ability in L1 and FL in addition to, phonological awareness, auditory working memory and musical aptitude, elements related to the acoustic dimension of reading, would influence adults' silent reading fluency. Our structural modeling allows us to describe how these different variables interact to determine the silent reading fluency construct. In fact, the effect of musical aptitude on fluent silent reading in our model reveals to be stronger than phonological awareness or auditory working memory.

A Music-Mediated Language Learning Experience: Students' Awareness of Their Socio-Emotional Skills.

In a society where mobility, globalization and contact with people from other cultures have become its distinctive traits, the enhancement of plurilingualism and intercultural understanding should be of the utmost concern. From a positive psychology perspective, agency is the human capacity to affect other people positively or negatively through one's actions. This agentic vision can be related to mediation, a concept rooted in socio-cultural learning theory, where social interaction is considered a fundamental cornerstone in the development of cognition. These social interactions in the language learning setting may be facilitated through musical activities due to their social bonding effect. This paper tries to offer insights into how a music-mediated experience in language learning may develop students' interpersonal and collaborative competences to become active members of a more inclusive society. Mediation, considered to be a paradigm shift in the foreign language classroom and for different out-of-class language learning possibilities, could also provide an environment where learners maximize their emotional intelligence. Our paper focuses on this paradigm shift spearheaded by the Common European Framework for Languages Companion Volume (CEFR/CV) and the considerable repercussions it is bound to have for foreign language didactics, as cooperative tasks become central to foreign language learning. We hypothesize that mediated language learning experiences (MeLLEs) imply a socio-emotional change in learners, focusing on the others, on their needs and interests, by trying to help them understand texts, concepts or facilitating communication with their peers. An intervention with a music-MeLLE was designed and implemented in an L2 classroom of adult learners with divergent backgrounds. A self-assessment scale with mediation descriptors and the socio-emotional expertise scale (SEE) were administered. Results show that students become more mindful of their strengths, and of their capacity for collaboration and teamwork. This leads to more awareness of their mediation skills. Students' mediation skills correlate significantly with their socio-emotional skills - specifically with their expressivity. The implementation of a music-mediated experience also promoted tolerance and enhanced learners' intrinsic motivations for language learning at the same time as acknowledging their diversity.

Collaborative stepped care for somatoform disorders: A pre-post-intervention study in primary care.

OBJECTIVE: The successful management of somatoform disorders in primary care is often limited due to low diagnostic accuracy, delayed referral to psychotherapy, and unstructured overuse of health care. This study aimed to investigate the feasibility of establishing a collaborative stepped health care network for somatoform disorders, and its impact on the diagnostic process and treatment recommendations in primary care. METHOD: The Network for Somatoform and Functional Disorders (Sofu-Net) was established to connect 41 primary care physicians (PCP), 35 psychotherapists, and 8 mental health clinics. To evaluate Sofu-Net, primary care patients at high risk of having a somatoform disorder were identified using the Patient Health Questionnaire, and were assessed in detail at the patient and PCP level. Discussion of psychosocial distress in the consultations, diagnostic detection rates and treatment recommendations were compared before and 12 months after establishing the network. RESULTS: Out of the pre- (n=1645) and 12-months-post Sofu-Net patient samples (n=1756), 267 (16.2%) and 269 (15.3%) high-risk patients were identified. From these, 156 and 123 patients were interviewed and information was assessed from their PCP. Twelve months after Sofu-Net establishment, high-risk patients more frequently discussed psychosocial distress with their PCP (63.3% vs. 79.2%, p<.001). PCPs prescribed more antidepressants (3.8% vs. 25.2%, p<.001) and less benzodiazepines (21.8% vs. 6.5%, p<.001). Sofu-Net did not affect PCP's diagnostic detection rates or recommendation to initiate psychotherapy. CONCLUSION: The study results indicate feasibility of an interdisciplinary network for somatoform disorders. Collaborative care networks for somatoform disorders have the potential to improve doctor-patient-communication and prescription behavior.

Musical plus phonological input for young foreign language readers.

Based on previous studies showing that phonological awareness is related to reading abilities and that music training improves phonological processing, the aim of the present study was to test for the efficiency of a new method for teaching to read in a foreign language. Specifically, we tested the efficacy of a phonological training program, with and without musical support that aimed at improving early reading skills in 7-8-year-old Spanish children (n = 63) learning English as a foreign language. Of interest was also to explore the impact of this training program on working memory and decoding skills. To achieve these goals we tested three groups of children before and after training: a control group, an experimental group with phonological non-musical intervention (active control), and an experimental group with musical intervention. Results clearly point to the beneficial effects of the phonological teaching approach but the further impact of the music support was not demonstrated. Moreover, while children in the music group showed low musical aptitudes before training, they nevertheless performed better than the control group. Therefore, the phonological training program with and without music support seem to have significant effects on early reading skills.

Linfedema de genitales externos: Presentación de un caso / External genitalia lymphedema: Case report

Objetivo: El linfedema de pene y escroto produce una monstruosa deformidad con afectación psíquica y en ocasiones una angustia mental extrema. El pene se encuentra escondido en el tejido escrotal, deformado, engrosado, edematoso e incurvado. El escroto se convierte en una gran masa de piel muy gruesa, dura, a veces agrietada, con exudación y fetidez. La erección y el acto sexual no son posibles o muy difíciles y el propio aumento escrotal interfiere con la marcha. Aportar un nuevo caso de linfedema de genitales externos masculino. Método/Resultados: Se presenta una variante técnica del tratamiento quirúrgico del linfedema primario de pene y escroto en un paciente de 32 años, portador de esta afección, de varios años de evolución y sometido a múltiples tratamientos medicamentosos y quirúrgicos, tales como linfagioplástia con aguja y fasciotomía en raíz del pene. La técnica quirúrgica empleada consistió en la realización de dos incisiones en w- plastia, una al nivel de la raíz del pene y la otra en la mucosa prepucial respetada, se extirpó todo el tejido linfedematoso, realizándose la reconstrucción con la mucosa prepucial y una pequeña zona de piel no infiltrada de la raíz del pene. En las bolsas escrotales previa extracción de su lecho del cordón espermático y los testículos para facilitar la operación, minimizar el tiempo quirúrgico y producir menos complicaciones, se efectuaron 2 colgajos cutáneos laterales en alas de mariposa, se liberaron los testículos y se resecó todo el tejido linfedematoso junto con un gran fragmento de bolsa escrotal, la reconstrucción se realizó a partir de la piel sana de la zona adyacente. Conclusiones: No se hizo necesario, con esta técnica, realizar injerto libre ni pediculado de piel. El paciente recuperó la capacidad funcional del pene, tuvo mejoría estética y desapareció la angustia que esta enfermedad le ocasionaba(AU)

Objectives: Penile and scrotal lymphedema produces a monstrous deformity with psychological impact and occasionally extreme mental anguish. The penis is buried in the scrotal tissue, deformed, thickened, edematous, and curved. The scrotum changes to a great, very thick, hard skin mass, sometimes cracked, exudative, and fetid. Erection and sexual intercourse are very difficult or impossible, and the scrotal enlargement interferes with walking. To report a new case of male external genitalia lymphedema. Methods/Results: We present a technical variation of the surgical treatment of penile-scrotal primary lymphedema in a 32-year-old patient suffering this disease for several years, which had underwent several medical and surgical treatments, such as lymphangioplasty and penile root fasciotomy. Observation consisted in the performance of two incisions in w-plasty, one at the root of the penis, the other one in the preserved preputial mucosa, and excision of all the lymphedematous tissue with reconstruction using the preputial mucosa and a small area of non infiltrated skin at the root of the penis. In the scrotum, two butterfly-wing shape skin flaps were performed; the testicles and the spermatic cord were isolated to ease the operation, minimize the surgical time and avoid complications; the lymphedematous tissue was resected with a great fragment of scrotum; finally reconstruction was performed from the adjacent healthy skin. Conclusions: With this technique it was not necessary to perform a free or vascularized skin graft. The patient recovered his penile functional capacity, improved aesthetically and his anguish disappear(AU)

[External genitalia lymphedema. Case report]. / Linfedema de genitales externos. Presentación de un caso.

OBJECTIVES: Penile and scrotal lymphedema produces a monstrous deformity with psychological impact and occasionally extreme mental anguish. The penis is buried in the scrotal tissue, deformed, thickened, edematous, and curved. The scrotum changes to a great, very thick, hard skin mass, sometimes cracked, exudative, and fetid. Erection and sexual intercourse are very difficult or impossible, and the scrotal enlargement interferes with walking. To report a new case of male external genitalia lymphedema. METHODS/RESULTS: We present a technical variation of the surgical treatment of penile-scrotal primary lymphedema in a 32-year-old patient suffering this disease for several years, which had underwent several medical and surgical treatments, such as lymphangioplasty and penile root fasciotomy. Observation consisted in the performance of two incisions in w-plasty, one at the root of the penis, the other one in the preserved preputial mucosa, and excision of all the lymphedematous tissue with reconstruction using the preputial mucosa and a small area of non infiltrated skin at the root of the penis. In the scrotum, two butterfly-wing shape skin flaps were performed; the testicles and the spermatic cord were isolated to ease the operation, minimize the surgical time and avoid complications; the lymphedematous tissue was resected with a great fragment of scrotum; finally reconstruction was performed from the adjacent healthy skin. CONCLUSIONS: With this technique it was not necessary to perform a free or vascularized skin graft. The patient recovered his penile functional capacity improved aesthetically and his anguish disappear.

Linfedema de genitales externos: Presentación de un caso / External genitalia lymphedema. Case report

Objetivo: El linfedema de pene y escroto produce una monstruosa deformidad con afectación psíquica y en ocasiones una angustia mental extrema. El pene se encuentra escondido en el tejido escrotal, deformado, engrosado, edematoso e incurvado. El escroto se convierte en una gran masa de piel muy gruesa, dura, a veces agrietada, con exudación y fetidez. La erección y el acto sexual no son posibles o muy difíciles y el propio aumento escrotal interfiere con la marcha. Aportar un nuevo caso de linfedema de genitales externos masculino. Método/Resultados: Se presenta una variante técnica del tratamiento quirúrgico del linfedema primario de pene y escroto en un paciente de 32 años, portador de esta afección, de varios años de evolución y sometido a múltiples tratamientos medicamentosos y quirúrgicos, tales como linfagioplástia con aguja y fasciotomía en raíz del pene. La técnica quirúrgica empleada consistió en la realización de dos incisiones en w- plastia, una al nivel de la raíz del pene y la otra en la mucosa prepucial respetada, se extirpó todo el tejido linfedematoso, realizándose la reconstrucción con la mucosa prepucial y una pequeña zona de piel no infiltrada de la raíz del pene. En las bolsas escrotales previa extracción de su lecho del cordón espermático y los testículos para facilitar la operación, minimizar el tiempo quirúrgico y producir menos complicaciones, se efectuaron 2 colgajos cutáneos laterales en alas de mariposa, se liberaron los testículos y se resecó todo el tejido linfedematoso junto con un gran fragmento de bolsa escrotal, la reconstrucción se realizó a partir de la piel sana de la zona adyacente. Conclusiones: No se hizo necesario, con esta técnica, realizar injerto libre ni pediculado de piel. El paciente recuperó la capacidad funcional del pene, tuvo mejoría estética y desapareció la angustia que esta enfermedad le ocasionaba (AU)

Objectives: Penile and scrotal lymphedema produces a monstrous deformity with psychological impact and occasionally extreme mental anguish. The penis is buried in the scrotal tissue, deformed, thickened, edematous, and curved. The scrotum changes to a great, very thick, hard skin mass, sometimes cracked, exudative, and fetid. Erection and sexual intercourse are very difficult or impossible, and the scrotal enlargement interferes with walking. To report a new case of male external genitalia lymphedema. Methods/Results: We present a technical variation of the surgical treatment of penile-scrotal primary lymphedema in a 32-year-old patient suffering this disease for several years, which had underwent several medical and surgical treatments, such as lymphangioplasty and penile root fasciotomy. Observation consisted in the performance of two incisions in w-plasty, one at the root of the penis, the other one in the preserved preputial mucosa, and excision of all the lymphedematous tissue with reconstruction using the preputial mucosa and a small area of non infiltrated skin at the root of the penis. In the scrotum, two butterfly-wing shape skin flaps were performed; the testicles and the spermatic cord were isolated to ease the operation, minimize the surgical time and avoid complications; the lymphedematous tissue was resected with a great fragment of scrotum; finally reconstruction was performed from the adjacent healthy skin. Conclusions: With this technique it was not necessary to perform a free or vascularized skin graft. The patient recovered his penile functional capacity, improved aesthetically and his anguish disappear (AU)

Canine infection and the possible role of dogs in the transmission of American tegumentary leishmaniosis in Salta, Argentina.

Some Leishmania species affect humans in two principal forms: visceral and cutaneous leishmaniosis (CL). Several studies have identified dogs as the main reservoirs of the visceral leishmaniosis (VL) caused by Leishmania infantum. The purpose of this work was to carry out a survey of the canine population associated with human cases of American tegumentary leishmaniosis (ATL), in order to establish the clinical, parasitological, serological and immunological characteristics of the canine disease, in an endemic region for both ATL and Chagas' disease in the province of Salta, in northwestern Argentina. Two hundred and eight dogs from the endemic area were examined and 41 (19.7%) of them presented lesions compatible with leishmaniosis. In order to investigate the presence of antibodies against Leishmania spp. and Trypanosoma cruzi, sera were screened by ELISA using two complex antigens from these parasites and, because of cross-reactions between them, a specific antigen for diagnosis of T. cruzi infection. Sixty-two (29.8%) of 208 dogs were positive for the complex antigen F45 from Leishmania and 50 (24%) were positive for the complex antigen F105 from T. cruzi. Nine dogs (4.3%) were positive for the specific Ag163B6-cruzipain suggesting that these dogs were truly infected with T. cruzi. Furthermore, three of these nine dogs presented Leishmania sp. in their skin lesions and therefore were considered as infected by both, T. cruzi and Leishmania parasites. The prevalence of Leishmania infection detected by lesions and/or positive serology was 27.4% (57/208). On the basis of previous observations regarding the clustered appearance of human ATL, the dog population was divided into two groups: zone A, dogs living within a 100 m radius from houses with human cases, and zone B, dogs living beyond this limit. The prevalence of ATL in dogs was significantly higher in zone A (34.6%) than in zone B (7.3%), suggesting a strong correlation between canine and human cases. The average time required for a parasitological diagnosis by microscopy was six times longer for dog samples than human ones, and the average number of parasites per 100 microscopic fields was 14-fold lower in canine samples. The high prevalence of Leishmania infection and the close association with human cases, demonstrated that dogs are a very susceptible host for Leishmania infection, but the scarcity of parasites in their lesions suggests that they may not be the main reservoir of the parasite in this endemic area.

[The transmission de Chagas disease in Salta and the detection of congenital cases]. / La transmisión de la enfermedad de Chagas en Salta y la detección de casos congénitos.

Data on the prevalence of Trypanosoma cruzi infection is presented for the province of Salta, Argentina. Special emphasis is given to the detection of congenital transmission and to the economic benefits of preventing Chagas' disease. Seroepidemiological data obtained from 20 year old army draftees revealed a reduction, from 22.7 to 11.11% between 1964 and 1985. In university students, a rate of 0.96% was found in 1998. Surveys carried out during 1996 showed that more than 15% of the pregnant women analyzed carried T. cruzi infection, particularly in the north of the province. This situation brings about a high risk of appearance of congenital cases and represents an opportunity to test the most adequate strategies for detection. By applying systematically microhematocrit, hemoculture and PCR methods, to umbilical chord blood, an increase in the early detection of congenitally infected babies is being achieved. In 1992-94, very high seroprevalence rates of infection were found among indians of the Chaco region of Salta. The overall rate was 37%, but there were 5 localities where more than 54% of the population was infected. These numbers indicate that, in vast areas of the provincial territory, fight against vector bugs must not merely consist of surveilance activities, but rather of renewed spraying attacks. The fight must include control of pregnant women and blood banks. An economic analysis of the economic return, calculated only for spraying activities and for the Department of Anta (Salta), indicated a net present value of over 7 million dollars and an internal rate of return exceeding 60%.

Preferential formation and decreased removal of cisplatin-DNA adducts in Chinese hamster ovary cell mitochondrial DNA as compared to nuclear DNA.

Levels of DNA adducts in Chinese hamster ovary (CHO) cells exposed to cis-diamminedichloroplatinum(II) (cisplatin) for 24 h, have been shown to be 4- to 6-fold higher in mitochondrial (mt) DNA as compared to nuclear (n) DNA (Olivero et al., Mutation Res., 346 (1995) 221). The aim of the present study was to understand if the preferential cisplatin binding in mtDNA is partially caused by lack of adduct removal in the mitochondria. Chinese hamster ovary cells were exposed for 6 h to 50 microM cisplatin, followed by incubation for 24 and 48 h in cisplatin-free medium. At the 30-h time point (6 h with cisplatin, 24 h without cisplatin), half of the cells from each plate were harvested and the remainder were cultured and harvested at 54 h (6 h with cisplatin, 48 h without cisplatin). The 30- and 54-h time points are called 'T30' and 'T54', respectively. Cisplatin-DNA adducts were measured in DNA from nuclear and mitochondrial fractions by dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA), a sensitive competitive microtiter-based immunoassay utilizing antiserum elicited against cisplatin-modified DNA. An initial higher level of cisplatin-DNA adducts was observed in mtDNA when compared to nDNA, at T30. In addition, a lack of removal of adducts in mtDNA was demonstrated in cells at T54. Dilution of DNA adducts by DNA replication was documented in pulse-chase experiments that employed [3H]thymidine incorporation. Adduct removal by repair-related mechanisms was considered to comprise the difference between total DNA adduct removal and adduct removal related to DNA replication. The final results demonstrated that both, higher initial binding and lack of removal of cisplatin-DNA adducts appear to contribute to the preferential cisplatin-mtDNA binding observed in CHO cells.

[Usefulness of exercise Doppler in the diagnosis of severe mitral stenosis]. / Valor del Doppler de esfuerzo para el diagnóstico de la estenosis mitral severa.

BACKGROUND: Exercise in mitral stenosis produces an increase in cardiac output and heart rate which determines the increment in the transmitral gradient. However, it has not yet been established what level is reached by the gradients on exercise in severe mitral stenosis nor whether the rise in the gradient during such exercise is different to that occurring in non-severe stenosis. OBJECTIVE: To evaluate the effect of exercise in patients with severe mitral stenosis on the mitral valve gradients in absolute values and on the increment with respect to base values. METHODS: Forty-eight mitral stenosis patients (mean age: 48.8 +/- 11 years) underwent 50 exercise Doppler echocardiographic studies using supine bicycle ergometry in two stages with increases of 25 W every 3 minutes; from each of these we obtained the peak and mean mitral gradient using a non-imaging continuous-wave Doppler probe. We also conducted this procedure on 14 patients with a mean age of 50 +/- 6 who had Bjork mitral prostheses which were functioning normally. RESULTS: We defined a hemodynamic profile of severity based on the data from 18 patients whose basal mitral valve areas was < 1.2 cm2 (group I), and compared them with the data from the 32 studies of mitral stenosis patients with an area > 1.1 cm2 (group II) and with the patients with mitral prostheses (group III). The mean mitral gradient (mmHg) in group I was greater than in group II at rest (9.3 +/- 3.2 and 6.6 +/- 2.7; p < 0.001), at 25 W (20.6 +/- 4.8 and 14.1 +/- 5; p < 0.001) and at 50 W (25.9 +/- 5.4 and 17.3 +/- 5.8; p < 0.001). The increase in mean mitral gradient from the baseline to 50 watts was 16.7 +/- 4.5 mmHg in group I, which was greater than in group II and III (11.1 +/- 4.1 and 6.8 +/- 2.6 mmHg; p < 0.001). CONCLUSIONS: Exercise Doppler echocardiography enabled us to define a differential hemodynamic profile in patients with severe mitral stenosis which can be used in isolation as an indicator of severity in this condition.

The effect of L-carnitine on the AZT-induced destruction of human myotubes. Part II: Treatment with L-carnitine improves the AZT-induced changes and prevents further destruction.

BACKGROUND: Zidovudine (AZT) as used in the treatment of AIDS causes a mitochondrial myopathy characterized by enzymatic defects in the respiratory chain system, accumulation of lipid droplets, and carnitine deficiency. Human myotubes treated with AZT demonstrate abnormal mitochondria, accumulation of lipid, and increased lysosomes. Because L-carnitine plays a major role in the transport of long chain fatty acids across the inner mitochondrial membrane and facilitates the beta-oxidation of fatty acids, we examined whether L-carnitine can enhance the recovery of the affected myotubes after withdrawal of AZT and can improve the structural changes of the myotubes while AZT treatment continues. EXPERIMENTAL DESIGN: Myotubes, prepared from human muscle biopsies, were exposed to 250 microM of AZT for 3 to 6 weeks. After 3 weeks of AZT treatment, the cultures were treated with L-carnitine or medium for 3 weeks, while AZT treatment was either withdrawn or continued for 3 more weeks. The cultures were evaluated with: (a) light microscopy; (b) immunocytochemistry, to count the number of myotubes stained with antibodies to Leu-19; (c) oil red O stain, to assess the lipid droplet accumulation; and (d) electron microscopy, to count all the organelles within representative sections of the myotubes, at x24,000, and to calculate the volumetric density (Vvi) of each organelle per unit volume of tissue. RESULTS: In the post-AZT-treated cultures, L-carnitine increased the number of Leu-19-positive myotubes from 3.83 +/- 1.23 to 23 +/- 1.5 per field, normalized their mitochondria, decreased the lipid droplets, and increased the Vvi of the myofibrils. In the cultures treated with 3 weeks of L-carnitine while AZT treatment continued for 3 more weeks, the number of myotubes increased from 3.3 +/- 0.74 to 6.87 +/- 1.35; the absolute number of the mitochondria increased from 1.65 +/- 0.35 to 9.02 +/- 1.11 and their Vvi from 3.67 +/- 0.83 to 6.57 +/- 0.78 (p < 0.05); the Vvi of the myofibrils increased from 2.50 +/- 0.52 to 5.37 +/- 0.76 (p < 0.05); and the Vvi of the lipid droplets decreased from 5.06 +/- 1.44 to 2.72 +/- 0.72 (p < 0.05). In the AZT-treated cultures that did not receive L-carnitine, the mitochondria demonstrated extensive vacuolation, abnormal cristae, and paracrystalline inclusions; in contrast, in the L-carnitine-treated cultures, the mitochondria had substantially improved in spite of continuation of AZT. CONCLUSIONS: L-carnitine enhances the pace and degree of recovery of the AZT-associated destruction of human myotubes, restores and preserves the structure of mitochondria, mobilizes the endomyotubular fat, and allows the regeneration of myofibrils, even if AZT treatment continues. The findings may have potential clinical implications in improving the myotoxicity of AZT in patients with AIDS when the administration of AZT treatment must continue.

Effect of L-carnitine on the zidovudine-induced destruction of human myotubes. Part I: L-carnitine prevents the myotoxicity of AZT in vitro.

BACKGROUND: Zidovudine (AZT) as used in the treatment of AIDS, causes a mitochondrial myopathy characterized by depletion of mitochondrial DNA, enzymatic defects in the respiratory chain system, and accumulation of lipid droplets. Most of these changes are also seen in normal human myotubes treated with AZT. Because L-carnitine plays a major role in the transport of long chain fatty acids across the inner mitochondrial membrane and facilitates the beta-oxidation of fatty acids, we examined the effect of L-carnitine in preventing the destructive effect of AZT on the mitochondria and the myotubes of human muscle in tissue culture. EXPERIMENTAL DESIGN: Myotubes, prepared from human muscle biopsies, were exposed to various concentrations of AZT for up to 3 weeks. One-third of the flasks were treated with AZT alone, another third with AZT plus L-carnitine and another third were untreated. The cultures were evaluated with: (a) immunocytochemistry counting the number of myotubes stained with antibodies to Leu-19; (b) enzyme histochemistry for NADH reaction and oil-red-O stain to assess mitochondrial enzymatic activity and lipid droplet accumulation; and (c) electron microscopy counting all the organelles within representative sections of the myotubes, at x24,000, and calculating the volumetric density of each organelle/unit volume of tissue. RESULTS: AZT, at concentrations 250 microM and above, caused depopulation of the Leu-19-positive myotubes, destructive changes in the mitochondria consisting of swelling, lamellar inclusions and multiple concentric cristae, accumulation of lipid droplets, and increase lysosomes. L-Carnitine increased the number of Leu-19-positive myotubes from 3.4 +/- 0.6 to 9.4 +/- 1.2, preserved the morphology of the mitochondria, increased their volumetric density from 2.5 +/- 0.4 to 6.0 +/- 0.7, and reduced the volumetric density of the lipid droplets from 12.2 +/- 4.9 to 1.4 +/- 0.7 and of the lysosomes from 15.6 +/- 3.6 to 3.9 +/- 1.4 (p < 0.001). CONCLUSIONS: L-Carnitine, used concurrently with AZT, prevents the human myotubes from the AZT-associated destruction, preserves the structure and volume of mitochondria and prevents the accumulation of lipids. The findings may have potential clinical implications in preventing the myotoxicity of AZT in patients with AIDS.

Field trial of vaccination against American trypanosomiasis (Chagas' disease) in dogs.

In Santiago del Estero, an area endemic for Chagas' disease in northwestern Argentina, household dogs were vaccinated with live-attenuated Trypanosoma cruzi, and the prospective incidence of natural infection by this parasite was assessed during a two-year followup period. Vaccinated dogs received 10(7) attenuated, TCC strain T. cruzi epimastigotes and were given booster vaccinations two and 14 months later. The number of animals that could be evaluated in vaccinated versus control groups was 73 and 75 after one year and 49 and 40 after two years, respectively. Parasitologic evaluation by xenodiagnosis indicated that vaccination had reduced natural T. cruzi infection from 26.7% to 12.3% after one year (P = 0.015). The preventive effect of vaccination after the second year was less significant in spite of the booster vaccinations. Inclusion of indirect hemagglutination data for the diagnosis of infection slightly increased the number of infected dogs without affecting the evidence for protection in the first year. Serologic, parasitologic, and isoenzyme studies indicated that protection was mediated by an attenuated, self-cured infection. In 15 dogs in which the vaccination failed to completely prevent natural infection, immunization nevertheless impaired their ability to infect the natural insect vectors of the disease in humans.

[Prevalence of dental agenesis in an Andalucian population]. / Prevalencia de la agenesia dentaria en la población Andaluza.

We have study oligodontia in a sample of Andalucias children. The population was between five and twelve years old. The authors wished to determine the prevalence of Oligodontia excluding third molars (the prevalence was higher than other spanish studies about the same subject). The mandibular second premolar was the most frequently absent tooth.

[Relationship of caries and periapical lesions in children]. / Relación entre caries y lesiones periapicales en población infantil.

Periapical lesion is an alteration of the bone around the dental apex. We pretended study periapical lesions appear in children's population. We proved a great relation between periapical lesion and carries. Then it was measured stadistically the relationship between both parameters.